// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file. See the AUTHORS file for names of contributors.

#include <sys/types.h>

#include "gtest/gtest.h"
#include "db/db_impl.h"
#include "db/filename.h"
#include "db/log_format.h"
#include "db/version_set.h"
#include "leveldb/cache.h"
#include "leveldb/db.h"
#include "leveldb/table.h"
#include "leveldb/write_batch.h"
#include "util/logging.h"
#include "util/testutil.h"

namespace leveldb {

    static const int kValueSize = 1000;

    class CorruptionTest : public testing::Test {
    public:
        CorruptionTest()
                : db_(nullptr),
                  dbname_("/memenv/corruption_test"),
                  tiny_cache_(NewLRUCache(100)) {
            options_.env = &env_;
            options_.block_cache = tiny_cache_;
            DestroyDB(dbname_, options_);

            options_.create_if_missing = true;
            Reopen();
            options_.create_if_missing = false;
        }

        ~CorruptionTest() {
            delete db_;
            delete tiny_cache_;
        }

        Status TryReopen() {
            delete db_;
            db_ = nullptr;
            return DB::Open(options_, dbname_, &db_);
        }

        void Reopen() { ASSERT_LEVELDB_OK(TryReopen()); }

        void RepairDB() {
            delete db_;
            db_ = nullptr;
            ASSERT_LEVELDB_OK(::leveldb::RepairDB(dbname_, options_));
        }

        void Build(int n) {
            std::string key_space, value_space;
            WriteBatch batch;
            for (int i = 0; i < n; i++) {
                // if ((i % 100) == 0) std::fprintf(stderr, "@ %d of %d\n", i, n);
                Slice key = Key(i, &key_space);
                batch.Clear();
                batch.Put(key, Value(i, &value_space));
                WriteOptions options;
                // Corrupt() doesn't work without this sync on windows; stat reports 0 for
                // the file size.
                if (i == n - 1) {
                    options.sync = true;
                }
                ASSERT_LEVELDB_OK(db_->Write(options, &batch));
            }
        }

        void Check(int min_expected, int max_expected) {
            int next_expected = 0;
            int missed = 0;
            int bad_keys = 0;
            int bad_values = 0;
            int correct = 0;
            std::string value_space;
            Iterator *iter = db_->NewIterator(ReadOptions());
            for (iter->SeekToFirst(); iter->Valid(); iter->Next()) {
                uint64_t key;
                Slice in(iter->key());
                if (in == "" || in == "~") {
                    // Ignore boundary keys.
                    continue;
                }
                if (!ConsumeDecimalNumber(&in, &key) || !in.empty() ||
                    key < next_expected) {
                    bad_keys++;
                    continue;
                }
                missed += (key - next_expected);
                next_expected = key + 1;
                if (iter->value() != Value(key, &value_space)) {
                    bad_values++;
                } else {
                    correct++;
                }
            }
            delete iter;

            std::fprintf(
                    stderr,
                    "expected=%d..%d; got=%d; bad_keys=%d; bad_values=%d; missed=%d\n",
                    min_expected, max_expected, correct, bad_keys, bad_values, missed);
            ASSERT_LE(min_expected, correct);
            ASSERT_GE(max_expected, correct);
        }

        void Corrupt(FileType filetype, int offset, int bytes_to_corrupt) {
            // Pick file to corrupt
            std::vector<std::string> filenames;
            ASSERT_LEVELDB_OK(env_.target()->GetChildren(dbname_, &filenames));
            uint64_t number;
            FileType type;
            std::string fname;
            int picked_number = -1;
            for (size_t i = 0; i < filenames.size(); i++) {
                if (ParseFileName(filenames[i], &number, &type) && type == filetype &&
                    int(number) > picked_number) {  // Pick latest file
                    fname = dbname_ + "/" + filenames[i];
                    picked_number = number;
                }
            }
            ASSERT_TRUE(!fname.empty()) << filetype;

            uint64_t file_size;
            ASSERT_LEVELDB_OK(env_.target()->GetFileSize(fname, &file_size));

            if (offset < 0) {
                // Relative to end of file; make it absolute
                if (-offset > file_size) {
                    offset = 0;
                } else {
                    offset = file_size + offset;
                }
            }
            if (offset > file_size) {
                offset = file_size;
            }
            if (offset + bytes_to_corrupt > file_size) {
                bytes_to_corrupt = file_size - offset;
            }

            // Do it
            std::string contents;
            Status s = ReadFileToString(env_.target(), fname, &contents);
            ASSERT_TRUE(s.ok()) << s.ToString();
            for (int i = 0; i < bytes_to_corrupt; i++) {
                contents[i + offset] ^= 0x80;
            }
            s = WriteStringToFile(env_.target(), contents, fname);
            ASSERT_TRUE(s.ok()) << s.ToString();
        }

        int Property(const std::string &name) {
            std::string property;
            int result;
            if (db_->GetProperty(name, &property) &&
                sscanf(property.c_str(), "%d", &result) == 1) {
                return result;
            } else {
                return -1;
            }
        }

        // Return the ith key
        Slice Key(int i, std::string *storage) {
            char buf[100];
            std::snprintf(buf, sizeof(buf), "%016d", i);
            storage->assign(buf, strlen(buf));
            return Slice(*storage);
        }

        // Return the value to associate with the specified key
        Slice Value(int k, std::string *storage) {
            Random r(k);
            return test::RandomString(&r, kValueSize, storage);
        }

        test::ErrorEnv env_;
        Options options_;
        DB *db_;

    private:
        std::string dbname_;
        Cache *tiny_cache_;
    };

    TEST_F(CorruptionTest, Recovery
    ) {
    Build(100);
    Check(100, 100);
    Corrupt(kLogFile,
    19, 1);  // WriteBatch tag for first record
    Corrupt(kLogFile, log::kBlockSize
    + 1000, 1);  // Somewhere in second block
    Reopen();

    // The 64 records in the first two log blocks are completely lost.
    Check(36, 36);
}

TEST_F(CorruptionTest, RecoverWriteError
) {
env_.
writable_file_error_ = true;
Status s = TryReopen();
ASSERT_TRUE(!s.

ok()

);
}

TEST_F(CorruptionTest, NewFileErrorDuringWrite
) {
// Do enough writing to force minor compaction
env_.
writable_file_error_ = true;
const int num = 3 + (Options().write_buffer_size / kValueSize);
std::string value_storage;
Status s;
for (
int i = 0;
s.

ok() &&

i<num;
i++) {
WriteBatch batch;
batch.Put("a", Value(100, &value_storage));
s = db_->Write(WriteOptions(), &batch);
}
ASSERT_TRUE(!s.

ok()

);
ASSERT_GE(env_
.num_writable_file_errors_, 1);
env_.
writable_file_error_ = false;

Reopen();

}

TEST_F(CorruptionTest, TableFile
) {
Build(100);
DBImpl *dbi = reinterpret_cast<DBImpl *>(db_);
dbi->

TEST_CompactMemTable();

dbi->TEST_CompactRange(0, nullptr, nullptr);
dbi->TEST_CompactRange(1, nullptr, nullptr);

Corrupt(kTableFile,
100, 1);
Check(90, 99);
}

TEST_F(CorruptionTest, TableFileRepair
) {
options_.
block_size = 2 * kValueSize;  // Limit scope of corruption
options_.
paranoid_checks = true;

Reopen();

Build(100);
DBImpl *dbi = reinterpret_cast<DBImpl *>(db_);
dbi->

TEST_CompactMemTable();

dbi->TEST_CompactRange(0, nullptr, nullptr);
dbi->TEST_CompactRange(1, nullptr, nullptr);

Corrupt(kTableFile,
100, 1);

RepairDB();

Reopen();

Check(95, 99);
}

TEST_F(CorruptionTest, TableFileIndexData
) {
Build(10000);  // Enough to build multiple Tables
DBImpl *dbi = reinterpret_cast<DBImpl *>(db_);
dbi->

TEST_CompactMemTable();

Corrupt(kTableFile,
-2000, 500);

Reopen();

Check(5000, 9999);
}

TEST_F(CorruptionTest, MissingDescriptor
) {
Build(1000);

RepairDB();

Reopen();

Check(1000, 1000);
}

TEST_F(CorruptionTest, SequenceNumberRecovery
) {
ASSERT_LEVELDB_OK(db_->Put(WriteOptions(), "foo", "v1"));
ASSERT_LEVELDB_OK(db_->Put(WriteOptions(), "foo", "v2"));
ASSERT_LEVELDB_OK(db_->Put(WriteOptions(), "foo", "v3"));
ASSERT_LEVELDB_OK(db_->Put(WriteOptions(), "foo", "v4"));
ASSERT_LEVELDB_OK(db_->Put(WriteOptions(), "foo", "v5"));

RepairDB();

Reopen();

std::string v;
ASSERT_LEVELDB_OK(db_->Get(ReadOptions(), "foo", &v));
ASSERT_EQ("v5", v);
// Write something.  If sequence number was not recovered properly,
// it will be hidden by an earlier write.
ASSERT_LEVELDB_OK(db_->Put(WriteOptions(), "foo", "v6"));
ASSERT_LEVELDB_OK(db_->Get(ReadOptions(), "foo", &v));
ASSERT_EQ("v6", v);

Reopen();

ASSERT_LEVELDB_OK(db_->Get(ReadOptions(), "foo", &v));
ASSERT_EQ("v6", v);
}

TEST_F(CorruptionTest, CorruptedDescriptor
) {
ASSERT_LEVELDB_OK(db_->Put(WriteOptions(), "foo", "hello"));
DBImpl *dbi = reinterpret_cast<DBImpl *>(db_);
dbi->

TEST_CompactMemTable();

dbi->TEST_CompactRange(0, nullptr, nullptr);

Corrupt(kDescriptorFile,
0, 1000);
Status s = TryReopen();
ASSERT_TRUE(!s.

ok()

);

RepairDB();

Reopen();

std::string v;
ASSERT_LEVELDB_OK(db_->Get(ReadOptions(), "foo", &v));
ASSERT_EQ("hello", v);
}

TEST_F(CorruptionTest, CompactionInputError
) {
Build(10);
DBImpl *dbi = reinterpret_cast<DBImpl *>(db_);
dbi->

TEST_CompactMemTable();

const int last = config::kMaxMemCompactLevel;
ASSERT_EQ(1, Property("leveldb.num-files-at-level" +
NumberToString(last)
));

Corrupt(kTableFile,
100, 1);
Check(5, 9);

// Force compactions by writing lots of values
Build(10000);
Check(10000, 10000);
}

TEST_F(CorruptionTest, CompactionInputErrorParanoid
) {
options_.
paranoid_checks = true;
options_.
write_buffer_size = 512 << 10;

Reopen();

DBImpl *dbi = reinterpret_cast<DBImpl *>(db_);

// Make multiple inputs so we need to compact.
for (
int i = 0;
i < 2; i++) {
Build(10);
dbi->

TEST_CompactMemTable();

Corrupt(kTableFile,
100, 1);
env_.SleepForMicroseconds(100000);
}
dbi->CompactRange(nullptr, nullptr);

// Write must fail because of corrupted table
std::string tmp1, tmp2;
Status s = db_->Put(WriteOptions(), Key(5, &tmp1), Value(5, &tmp2));
ASSERT_TRUE(!s.

ok()

) << "write did not fail in corrupted paranoid db";
}

TEST_F(CorruptionTest, UnrelatedKeys
) {
Build(10);
DBImpl *dbi = reinterpret_cast<DBImpl *>(db_);
dbi->

TEST_CompactMemTable();

Corrupt(kTableFile,
100, 1);

std::string tmp1, tmp2;
ASSERT_LEVELDB_OK(
        db_->Put(WriteOptions(), Key(1000, &tmp1), Value(1000, &tmp2)));
std::string v;
ASSERT_LEVELDB_OK(db_->Get(ReadOptions(), Key(1000, &tmp1), &v));
ASSERT_EQ(Value(1000, &tmp2)
.

ToString(), v

);
dbi->

TEST_CompactMemTable();

ASSERT_LEVELDB_OK(db_->Get(ReadOptions(), Key(1000, &tmp1), &v));
ASSERT_EQ(Value(1000, &tmp2)
.

ToString(), v

);
}

}  // namespace leveldb

int main(int argc, char **argv) {
    testing::InitGoogleTest(&argc, argv);
    return RUN_ALL_TESTS();
}
